A camera such as a network camera may be used in many different situations, both indoors and outdoors, to monitor a scene. The camera is often arranged for rotation and/or tilting in order to enable image acquisition from different positions in the specific area.
The camera may comprise an at least partly transparent housing, such as a hemispherical dome window, and an imaging device arranged inside the housing and configured to capture images through the housing.
In environments where water vapour is present in the ambient air, the vapour may condense on the inside surface of the housing, also referred to as dew formation. Dew formation occurs when dew formation conditions are fulfilled, the dew formation conditions including air humidity, air temperature outside the camera and temperature inside the camera.
Dew formation may thus happen when the ambient temperature outside the camera drops, such as in the evening, and the air surrounding the camera cools down more quickly than the camera itself, resulting in the housing cooling down before the rest of the camera. Heat generated by the imaging device may also contribute to causing a temperature difference between the inside and the outside of the camera.
Prior art solutions addressing this issue may involve provision of a housing with a double-walled window structure with an insulated space (such as vacuum) separating the two windows of the window structure or provision of an air blowing nozzle powered by a fan directed towards the inner surface of the housing.